The risen village girl pushes her arm up through the earth. Subsequent shots show no damage to her coffin lid. Had she pushed open the lid at the same time as her arm broke through the surface the lid would have broken through as well.
During an unexpectedly brief stop in town, the stage coach abandons Marianne Danielle at the inn, with just the clothes on her back. Later that evening at the castle, she awakens in a night gown, with a dressing gown laid out on the bed. The next day she tells Van Helsing that her luggage is at the castle.
It is ridiculous to believe that Baron Meinster can be held prisoner by a simple chain attached to his ankle. Being a vampire, he has super human strength, and could easily break the chain off his leg. Secondly, he could simply change himself into a bat and slip out of the chain.
Baron Meinster throttles Van Helsing into unconsciousness, then bites him. Van Helsing "disinfects" the vampire's bites by searing them with a red-hot iron and completes the cure with holy water. Watch the closeup shot of Van Helsing as the burned area is healed - you can see a slight shift as the burnt and healed shots of Peter Cushing are exchanged.